A compressor, which is used in an automobile air conditioning system, is usually mounted on the engine of the automobile through a suitable mounting bracket. A normal mounting arrangement generally comprises a projection extending radially from the housing of the compressor and at least one bracket. The bracket is fixed on the engine and the compressor is fixed to the bracket by bolts. The compressor is thus mounted on the engine through the bracket.
Referring to FIG. 1, which illustrates the main portion of a conventional mounting mechanism, bracket 10 includes a base portion 101 fixed on the engine and flange portions 102 extending radially outwardly from base portion 101. A hole 102a is formed through an outer end portion of flange portion 102. A compressor 20 is also provided with a plurality of projections 201 extending radially outwardly from both end portions of the housing of compressor 20, and a hole 201a is formed through each projection 201. Adjacent projections 201 and flange portions 102 are connected by a bolt 30-nut 31 mechanism which includes washer elements 32. FIG. 1 illustrates one adjacent pair of projections 201 and flange portion 102, with another pair being located at the other end of the compressor housing. Compressor 20 is thus affixed on the engine through bracket 10.
In such a mounting construction, compressor 20 and mounting bracket 10, both of which are formed of high strength material, are directly connected through a bolt-nut mechanism. Mechanical vibration, more specifically vibration in the axial direction, which is generated by the operation of compressor 20, is thus transmitted directly to the engine, causing loud noise. This noise is transmitted from the engine compartment to the passenger compartment of the automobile.
One solution to the above disadvantages is disclosed in Japanese Utility Model Publication No. 57-61252. In this prior art publication, the compressor is connected with a mounting bracket by a bolt through a rubber member to thereby absorb the vibration of the compressor. However, the belt which is connected between the engine and the compressor should be under some tension in order to secure the transmission of rotating motion from the engine to the compressor. The rubber member is therefore locked to obtain the tension.